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HYBRID LASER WELDING of Aluminium. Jo Verwimp Lasercentrum Vlaanderen VITO. OUTLINE. The process Synergies Process combination Process parameters Experimental process parameter determination Joint geometries Experimental setup LCV Applications Demonstration. The process. Synergies.
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HYBRID LASER WELDING of Aluminium Jo Verwimp Lasercentrum Vlaanderen VITO
OUTLINE • The process • Synergies • Process combination • Process parameters • Experimental process parameter determination • Joint geometries • Experimental setup LCV • Applications • Demonstration
Process combination Alu 6082 T6, thickness 4 mm Welding speed = 1.2 m/min Nd:YAG Laser power = 3.8 KW MIG parameters: 90 A, 16 V, wire speed = 2.2 m/min + = Laser only MIG only Laser + MIG hybrid
Process parameters (1) MIG LASER • Arc: • Voltage • Current • Power source (DC, AC, pulse) • Pulse frequency • Stick out • Wire: • Speed • Diameter • Type • Other: • Torch orientation • Gas shielding • Edge preparation • Source: • Type (CO2 , Nd:YAG, ...) • Power • (Pulse frequency) • Optics: • Focal length • Spot size • Focal position • Single – double focus • Other: • Welding speed • Gas shielding • Edge preparation
Distance between laser focal point & impingement of the arc: • Determination of weld pool geometry • Bigger weld pool = easier outgassing • Small distance: interaction laser – MIG • Larger distance: interaction will become negligible • Geometrical formation of laser beam and arc torch • Angle between laser & MIG (normally fixed to 30°) • Laser leading or trailing (normally laser leading) • Shielding gas • CO2 laser: helium needed (to suppress plasma formation) • Nd:YAG: Ar pure or Ar/He (He gives higher penetration) Process parameters (2): interactions
Experimental process parameter determination 1. Laser only: determination of laser power - full weld penetration 2. Hybrid: determination of MIG parameters, based on: - visual inspection on weld appearance - no undercut, full penetration 3. Hybrid: interaction parameters - distance laser/MIG and gas shielding 4. Hybrid: fine tuning of laser & MIG parameters, based on - visual inspection, RX inspection - tensile tests, bend tests
Joint geometries Single: max. 5; double max. 8mm Fillet or Lap joint: max. 5 mm Lap-joint: max. 4 mm T-joint: single 4, double max. 6mm
Applications Automotive Volkswagen: Wolfsburg Audi: Neckersulm Mitsubishi: alu space frame Aviation Airbus Germany Research University of Aachen Fraunhofer Laser Institute Force Denmark, Vito CSIRO Melbourne, Institut de Soudure (FR) TWI Cambridge, JWRI Osaka Other businesses Piping, shipbuilding, construction, ... Audi A8: Neckersulm
Continuation: Experimental results by W. Van Haver Thank you